A novel fabrication approach for forming precisely positioned nanowire array structures is introduced. The approach is suitable for potentially economical and environmentally safe manufacturing. For the demonstration of this approach, 100nm wide Sn nanowires and 150nm wide polyaniline (PANI) nanowires were synthesized using an electro-chemical deposition technique and a process we term the step-and-grow method. The nanowires produced exhibit the expected properties. For example, synthesized PANI nanowires showed reasonable ranges of electrical conductivities (e.g., 25S/cm for a 200nm wide, 200nm high, 10um long nanowire), and formed ohmic contact with electrodes on a substrate. It is shown that the polydimethylsiloxane (PDMS) stepping template mold used for our step-and-grow nanowire synthesis process can be used at least up to 40 times without degradation.